For gas station, pump hoses are employed to convey oil to/from oil tanks. Such tanks are generally equipped with an oil input unit and an oil output unit in the inlet and outlet respectively. Each of units is further attached to a joint wherein a lever hinged to a flange on the joint is pressed down to secure the joint to the pump hose and the tank inlet/outlet respectively prior to pumping oil. However, after oil pumping complete an operator has to wait until the remained oil drains out of the pump hose and/or two-way valve prior to retracting a conventional pump hose equipped with two-way valve into place. Otherwise, the remained oil may leak from pump hose due to negligence. This is very dangerous. Further, there is no releasing unit provided in the connector of conventional joint and thus a high heat may be generated in the connector when pump hose is pulled by a strong force which in turn causes danger.